1. Field of the Invention
This invention relates generally to an electric power supply system for a camera and, more particularly, to a power supply system for a camera having a large capacity condenser for a stroboscopic tube, a signal processor for processing image signals from an image pick-up element, and at least a primary battery.
2. Description of the Background
Recently there have been proposed and developed various cameras that include a stroboscope or xenon flash tube and a signal processor. Generally, such cameras include a charging circuit and a large capacity condenser for momentarily supplying a large current to the stroboscope. Typically, a primary battery, such as an alkaline battery, is provided for the so-called flash and a secondary battery, such as a nickel-cadmium battery, is provided for the signal processor in such cameras. Usually, the stroboscope and the signal processor have a common power supply. Because the primary battery has a much greater internal resistance than the secondary battery, when the primary battery is used as the power supply for both the stroboscope and the signal processor, an excessive voltage drop relative to the signal processor occurs during operation of the stroboscope. This voltage drop is caused by the large current flowing from the condenser employed in the charging circuit for the stroboscope to the discharge element, that is, the flash tube. As a result of this voltage drop, the signal processor may operate erroneously or it may not operate at all. For this reason, this kind of camera requires a relatively large number of primary battery cells to provide a large enough power capacity to compensate for the voltage drop. The drawback of this is that such a camera is inconvenient to use because the large battery package is heavy and changing of the batteries is cumbersome.